LONDON (Reuters) - Gold rose for a fourth day on Wednesday as concerns over escalating tensions in Syria, U.S. sanctions on Russia and the U.S.-China trade stand-off weighed on stock markets and helped to knock the dollar index to a two-week low.

The metal reached its strongest in two weeks as appetite for nominally lower-risk assets sharpened. Palladium, which has also benefited from fears that sanctions on Russia could hurt supply, rose further after climbing nearly 6 percent in the past two days.

Spot gold (XAU=) was up 0.8 percent at $1,349.75 an ounce by 1155 GMT, having touched its highest in two weeks at $1,351.43. U.S. gold futures (GCcv1) rose 0.5 percent to $1,352.90.

"We've seen fears of a trade war and now more recently the Russian sanctions," said Capital Economics analyst Simona Gambarini. "Uncertainty, volatility and geopolitical risk have been rising steadily since the start of the year."

That has sparked good demand for gold through products such as bullion-backed exchange-traded funds, she said. "Gold is benefiting from the risk-off sentiment and because people are trying to hedge against worst-case scenarios."

European equities fell after two days of gains as tensions over Syria and U.S. sanctions drove Russia's rouble to a two-year low, while concerns about the prospect of a trade war boosted traditional safety plays at the dollar's expense.

The U.S. unit languished near a two-week low against a basket of currencies.

Gold is often perceived as a safe store of value during times of political and financial uncertainty.

Markets are also awaiting cues on the outlook for U.S. monetary policy from consumer inflation data and minutes from the Federal Reserve's March meeting, due later on Wednesday.

Among other precious metals, silver (XAG=) was up 0.2 percent at $16.59 an ounce, while platinum (XPT=) gained 0.5 percent to $928.50.

Palladium (XPD=) was up 0.4 percent at $955.72.

The metal, more than 40 percent of which is produced in Russia, has bounced strongly this week as sanctions against the country fed into a technically driven rebound after the first quarter's 10 percent slide.

Although Russian output of the metal has not been affected directly, the sanctions have caused enough concern over supply in a market that has been in deficit for a decade to bring some speculative money back in, analysts said.

"With (sanctions target) UC Rusal owning 28 percent of Norilsk Nickel, a significant producer of platinum group metals, traders remain wary that supplies of the precious metal may also be impacted," ANZ said in a note.

(Reporting by Jan Harvey in London; Additional reporting by Swati Verma in Bengaluru; Editing by Dale Hudson and David Goodman)